1. Field of Invention
This application is in the field of indicator knobs for electronic musical instrument amplifiers and related methods, including methods of construction.
2. Background
An amplifier (or amp) is an electronic amplifier which makes the signal of an electric musical instrument louder so that it will produce sound through a loudspeaker. Most amps may also be used to manipulate an instrument's tone by emphasizing or de-emphasizing certain frequencies within the electronic signal and/or supplementing the signal with electronic effects. Due to the multi-functionality of amps, most amps feature separate controls for each function. For example, many amplifiers feature a gain control, contour control, treble control, and the like. Many of an amp's functionality controls are driven via the turning of a knob, wherein manipulating the position of the knob modifies the sound quality produced by the associated musical instrument. Therefore, there is a need for an amplifier knob that provides an indication of whether or not it is presently influencing sound quality.
One attempt at meeting the above identified need is U.S. Pat. No. 7,036,188 (issued May 2, 2006) which discloses a “composite knob with light pipe leakage barrier.” In this patent, the knob features a back-lit light window across the front and side of the knob (element 33, FIG. 1; col. 2:10-11), which window emits light whenever the knob is presently influencing sound quality. Still referring to this patent, back-light is delivered to the window (element 33, FIG. 1) via a transparent light pipe (element 75, FIG. 7) within an opaque skirt (element 85, FIG. 7) (light enters the light pipe at its back edge and escapes out the edge(s) adjacent to the light window). Although the indicator knob disclosed in this patent is capable of indicating influenced sound quality in an amplifier, the disclosed knob is nevertheless not entirely suitable for that purpose. For instance, the disclosed knob is not suitable for indicating sound since the back edge of the light pipe (element 75, FIG. 7) must receive light in order for the light to present at the window (element 33, FIG. 1) whereby either of these unfavorable circumstances result: (A) an expensive light source must be fixedly positioned immediately behind the light-pipe so that said light source turns with the knob; (B) a plurality of expensive light sources must be positioned around the turning circumference of the knob; or (C) the intensity of light emission at the window must necessarily be weak due to poor angles of light entry into the light-pipe. See also U.S. Pat. No. 6,499,191 (Issued Dec. 31, 2002) (which discloses a backlit knob with light-pipe (element 55, FIG. 5)). Also, construction of such a knob requires many components, is complicated, and is relatively expensive. Thus, there remains a need for an amplifier knob that provides an indication of whether or not it is presently influencing sound quality without the unsatisfactory aspects of the knob of U.S. Pat. No. 7,036,188.
Other attempts at a solution to the above identified need are similarly or relatedly unsatisfactory. For example: the “control knob using LED for backlighting” of U.S. Pat. No. 6,003,206 (issued Dec. 21, 1999) is unsatisfactory since an expensive light source requiring electricity must be fixedly positioned within the knob behind the light window so that said light source turns with the knob (e.g., the knob is unsatisfactory since it requires a complex power system and assembly for the internal light). For another example, the “control knob with multi-color indicator” of U.S. Pat. No. 7,205,495 (Apr. 17, 2007) is unsatisfactory since: (A) it features a shell with a window positioned around a potentiometer with a translucent shaft and internal LED; and (B) such a potentiometer must be specifically customized to the knob, which is expensive. Thus, there remains a need for an amplifier knob that provides an indication of whether or not it is presently influencing sound quality without the unsatisfactory aspects of the previous attempts.